preg_match() warning in wp_image_add_srcset_and_sizes() when image_meta['file'] is missing

[enravo]

In the wp_image_add_srcset_and_sizes() function (wp-includes/media.php), the $image_meta['file'] key is used without checking if it exists.

When image metadata is incomplete or malformed (e.g. missing the file key), this causes the following issues on PHP 8+:

---

### Sample Error (PHP 8+):
Warning: Undefined array key "file" in wp-includes/media.php on line 1768

Deprecated: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated

### Problem Line (media.php:1768):

if ( preg_match( '/-e[0-9]{13}/', $image_meta['file'], $img_edit_hash ) )

Wrap the logic with a check for 'file' to ensure safe execution:

if ( ! empty( $image_meta['file'] )
     && preg_match( '/-e[0-9]{13}/', $image_meta['file'], $img_edit_hash )
     && ! str_contains( wp_basename( $image_src ), $img_edit_hash[0] ) ) {
    return $image;
}

#63394

[sabernhardt]

Hi and welcome to WordPress Core Trac!

#60480 already proposes to check for the 'file' array key in wp_image_add_srcset_and_sizes(). Please continue the discussion on that ticket.

Hi @narenin, I have updated the PR, please review it at your convenience.

Hi, just to clarify — I originally discovered and documented this issue in Trac Ticket #63394 and proposed a fix.

I also submitted a working PR on my own fork:
​https://github.com/Enravo/wordpress-develop/pull/1

The discussion and resolution here (PR #8772) is clearly based on that ticket and should credit the original discovery and proposal.

I'd appreciate it if you could add me to the props list.
GitHub: @Enravo
Thanks!

[enravo]

Correction: In my previous comment, "

PR #8772

" was meant to refer to the GitHub pull request:

​https://github.com/WordPress/wordpress-develop/pull/8772

Trac automatically linked it to an unrelated internal ticket. Apologies for the confusion.

Hi, just to clarify — I originally discovered and documented this issue in Trac Ticket #63394 and proposed a fix.

I also submitted a working PR on my own fork: ​Enravo#1

The discussion and resolution here (PR #8772) is clearly based on that ticket and should credit the original discovery and proposal.

I'd appreciate it if you could add me to the props list. GitHub: @Enravo Thanks!

Hi @Enravo,
The github-actions bot automatically generates the props, and as I can see now, it has added your name in props here: ​https://github.com/WordPress/wordpress-develop/pull/8772#issuecomment-2853523545. I have also added you in PR description.

I mentioned you on Trac 60480, where this effort should continue. You also added a comment there, so you should receive props.

I do not think this PR is the best direction. If the ! empty( $image_meta['file'] ) check is in the same conditional statement as the preg_match(), the wp_image_add_srcset_and_sizes() function might be able to continue without the filename and then pass incomplete metadata to wp_calculate_image_srcset() and/or wp_calculate_image_sizes().

Also, ! empty( $image_meta['file'] ) would cover the case of a missing 'file' key, without needing to add isset( $image_meta['file'] ).